PROJECT SUMMARY Cancer is the leading cause of death among Latinos in the U.S. The cancers with the highest estimated incidence rates among Latinos in 2015 were breast, prostate, and colorectal cancers ? all screenable cancers linked to preventable behaviors. Latinos are also more likely to be diagnosed with advanced stages of disease compared to non-Hispanic Whites; this has been associated with lower screening rates. Given this unequal burden of disease, it is important to identify ways to effectively reach and educate Latinos on how cancer prevention and screening can reduce these cancer health disparities. Social media presents an innovative platform to engage with Latinos dialogically by allowing user interaction through posts, pictures, videos and other information sharing. Due to its popularity, Facebook may be a useful platform for Latinos without a history of cancer to engage with cancer prevention and screening messages. This is particularly important among Latinos age 40-75, as they are eligible for breast, prostate and/or colorectal cancer screenings. The proposed mixed methods study will explore engagement with cancer messaging on Facebook among U.S. Latinos. Specific aims include: (1) examining engagement with cancer posts on the top national health Facebook Pages tailored to Latinos; (2) exploring how and why Latino adults age 40-75 without a history of cancer engage with cancer prevention and screening messages on Facebook; and (3) understanding how Latino adults age 40-75 without a history of cancer assess the credibility and accuracy of cancer messages they engage with on Facebook. Aim 1 will assess how Facebook users engaged with relevant cancer prevention and screening posts on NCI and CDC's Spanish-language Facebook Pages. Post likes, comments and/or shares between 2015 and 2017 will be analyzed via content analysis and logistic regressions. Aims 2 and 3 will be conducted concurrently during one-on-one, in-person encounters where the participant will access his/her Facebook profile, and scroll-through and discuss engagement with cancer-related posts with the researcher. Participants (n=30) will be recruited through stratified purposeful sampling, equally stratified by language preference and gender. Participants must self-identify as Latino/Hispanic; be 40-75 years old; have a Facebook account they use at least 3x a week; have no previous cancer diagnosis; and have a family member or close friend that is a cancer survivor. After completing a short demographics survey, participants will access their Facebook account alongside the researcher and walk-through the past six months of cancer messages posted on their Facebook NewsFeed. Participant engagement with content will prompt semi-structured, in-depth interviews discussing engagement with cancer messages. Data will be analyzed via content analysis and thematic analysis. Analyses for all three aims will be integrated to develop a final conceptual model. Findings will provide insight to specific attributes in cancer messages that attract user engagement and subsequent action, as well as how Latinos assess the credibility and accuracy of this information.